hdu 4165

Pills

#include<bits/stdc++.h>
using namespace std;
long long f[35];
int main()
{
	int i,n;
	f[1]=1;
	f[0]=1;
	for(i=2;i<=50;i++){
		for(int j=0;j<i;j++){
			f[i]+=f[j]*f[i-1-j];
		} 
	}
		while(scanf("%d",&n)!=EOF&&n!=0){
		printf("%lld\n",f[n]);
	}
	return 0;
}``